Subtract 18/30 from 7/90
7/90 - 18/30 is -47/90.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 30 is 90
Next, find the equivalent fraction of both fractional numbers with denominator 90 - For the 1st fraction, since 90 × 1 = 90,
7/90 = 7 × 1/90 × 1 = 7/90 - Likewise, for the 2nd fraction, since 30 × 3 = 90,
18/30 = 18 × 3/30 × 3 = 54/90 - Subtract the two like fractions:
7/90 - 54/90 = 7 - 54/90 = -47/90
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/90-18/30 7/90-36/30 7/90-18/60 21/90-18/30 7/90-54/30 7/90-18/90 35/90-18/30 7/90-90/30 49/90-18/30